1. Field of the Invention
The invention relates to a laminated ink jet recording head formed by bonding an actuator unit made of ceramic and a flow path substrate formed of metal together.
2. Description of the Prior Art
For example, as shown in Japanese Patent Publication No. Hei. 6-40035, an ink jet recording head is designed so that piezoelectric vibrators are stuck to a part of a resilient plate forming a pressure generating chamber and the volume of each pressure generating chamber is changed by flexural displacement of the corresponding piezoelectric vibrator. Therefore, the ink jet recording head can displace a wide area of the pressure generating chamber. Therefore, such an ink jet recording head can produce ink droplets stably.
As shown in FIG. 15, such a recording head can be roughly divided into actuator units A, B, C and a single flow path unit D. The plurality of actuator units A, B, C are prepared by sintering a ceramic material into pressure generating chambers, vibration plates, and piezoelectric vibrators. The flow path unit D is made of a metal plate formed so as to correspond to a plurality of arrays of nozzle openings. The plurality of actuator units A, B, C and the flow path unit D are fixed to one another using an adhesive.
As described above, the plurality of actuator units are fixed to the flow path unit by means of a thermally fusing method in which a fusible film is interposed between the actuator units and the flow path unit and in which the fusible film is fused by heating with pressure being applied thereto.
However, since the bonding area is large, the air contained between the fusible film and the actuator units/the flow path unit expands and thereby causes defective bonding. Further, since the materials are heated for a long period of time, a difference in thermal expansion due to a difference in materials causes warp and the like.
In addition to these problems, with a progress in the downsizing of recording heads, the problem of so-called "crosstalk" occurs because vibrations of the piezoelectric vibrators propagate to the common ink chambers, and this in turn causes the meniscuses of the other pressure generating chambers through the ink in the common ink chamber. As a result, the problem of impaired printing quality, e.g., is encountered.